How to Use Diatomaceous Earth for Lawns

by Angela Ryczkowski

Diatomaceous earth is a material composed of the fossilized skeletons of diatoms, tiny single-celled organisms. The skeletons have sharp edges and are porous, so the material scratches the protective coverings of insects and other pests and absorbs oils. It is particularly effective against soft-bodied slugs and snails that require regular moisture to survive. Diatomaceous earth, available as a powdery substance, is an organic, naturally occurring and nontoxic alternative to chemicals used as pesticides in the home landscape.

1 Put on a dust mask to handle or apply diatomaceous earth. Although this material is nontoxic, it can still irritate the respiratory tract if inhaled.

2 Pour or scoop diatomaceous earth into a garden duster or dust sprayer. A duster is not necessary, but makes it easier to apply the material uniformly and relatively quickly.

3 Dust the lawn area where you want to control pests, applying the material uniformly when the grass is dry and no rain is anticipated for at least a day. If you are using a duster, keep the nozzle close to the ground and sweep the duster back and forth, working from one side of the lawn to the other.

4 Sprinkle the diatomaceous earth in a protective circle around any particularly vulnerable plants, or dust the entire plant with the diatomaceous earth. If you are applying the material to protect your house against pests like ants, sprinkle the diatomaceous earth as a protective barrier around the structure.

5 Reapply the diatomaceous earth regularly in moist areas and after each rainfall while the problematic pests still pose a threat.

Items you will need

Dust mask

Scoop, if needed

Garden dust sprayer

Tip

Diatomaceous earth becomes less effective when it is wet, so it may not be ideal for use in areas that are typically very humid.

Warnings

Read the label of any diatomaceous earth product carefully. Some may be blended with chemical pesticides intended to make them more effective against certain pests.

The type of diatomaceous earth used in swimming pool filters has been altered by high temperatures and is not suitable for use or reuse in lawns or for pest control.

Avoid dusting blooming flowers with diatomaceous earth, because this material can injure bees and other beneficial insects that are pollinating the flowers.